Despite many disagreements on the utility of neuropsychological applications in schools, executive function measures have been found to be useful across a variety of areas and ages. In addition, many disagreements are extant in discussions of the maturational course of the development of executive functioning abilities that are dependent on functional capacity of the human brain, including the frontal lobes, among other brain areas. In part, these controversies are related to a dearth of standardized functional assessments of executive functioning abilities across wide age spans. This article describes several recent measures of executive functioning and uses life-span data from these assessments to project maturational periods of specific executive functions. Clinical implications of these results for school psychology assessment, rehabilitation of brain-injured school-aged children, and forensic practice of school psychology are posited. (Contains 12 figures.)